Oil immersed transformer
Oil immersed transformer is one of the important equipment in the power supply and distribution system of industrial and mining enterprises and civil buildings.
Oil immersed type transformer main types:
Both against high electrical stress due to external over voltages and against mechanical overloads by short circuits. The windings are made of copper or aluminum. Low-voltage windings are made of strip or flat wire, and the high voltage windings are manufactured from round or profile wire.
The three-limb iron core is made of oblique cut Grain-oriented, seven-step silicon steel laminations insulated on both sides, guaranteeing low losses and low noise. These values are even improved by laser treatment. It is protected on the surface with a flash-proof varnish in order to prevent the sheet from corrosion and to reduce the noise.
Special attention is paid to corrosion protection. Pretreatment of the surface is processed by phosphating pickling, contributes to corrosion protection, just like multi-coating with preset drying times for each layer. On request, hot-dip galvanization provides for even better protection.
For example, the high-voltage transformer for test, the transformer for electric furnace, the transformer for welding and the transformer for SCR line are used for the voltage transformer and current transformer of measuring instrument.
Dry type Power transformer
Dry type transformer is widely used in local lighting, high-rise buildings, airports, wharf CNC mechanical equipment and other places. It is especially suitable for installation and use in places with high fire protection requirements such as inflammable and explosive.
Clamping frame processed by CNC cutting, bending and then one-time punch forming, the hole’s size is accurate and the appearance looks delicate.
The winding coil is made of oxygen-free copper, class H for main insulation materials and coil is insulated by NOMEX paper of DUPONT brand, LV winding is isolated by copper foils. All these make the heat-resistant is up to 220℃, with excellent overload capacity and low loss, but high efficiency.
Insulation class H
Varelen practices strictly exclusive casting system of F(155℃) or H(180℃), and the epoxy resin is injected and casted in the vacuum machine, so it’s highly insulated, dust-proof and moisture-proof, which ensures stable and reliable performance.